Wheel motors are commonly used for the motorization of vehicles, such as bicycles, scooters, lightweight motorcycles, cars, etc. A wheel motor comprises a stator hub with windings, and a rotor wheel rotating about the hub. The rotor wheel comprises a plurality of magnets driven by the current in the windings. Advantageously, the wheel motor operates as a direct drive; there is no transmission to convert the motor output to a given speed. The power output of the wheel motor is as a function of the electrical current fed to the wheel motor.
There are continuous efforts to increase the power output from wheel motors. Some parameters can be used to alter the power output of the wheel motors, such as rotor size. However, there may be constraints to adjusting a rotor size, as wheels come in standard dimensions. For instance, bicycle wheels for adult bicycles typically come within standard diameters, such as 26 inches, 29 inches, 700 mm or 650 mm. In order to maximize the size of the motors, spokes are conventionally attached to an outer periphery of the motor casings, with substantially shorter spokes than usual for standard-diameter wheels. As spokes add to the comfort of the rider for instance by their flexing action, the shortening of the spokes may have an adverse effect on the riding experience.